Start-stop technology of an automobile engine is a new type of environmental friendly automobile technology that has been developed in recent years. According to this technology, when an idle speed condition is satisfied during the travelling of an automobile, the automobile engine will automatically stall so as not to operate. Conversely, when it is required to continue advancing, the automobile will quickly respond to a start command to quickly re-start the engine, thereby realizing an instant transition. Since the automobile engine does not work during each temporary stall, there is a reduction in fuel consumption and exhaust emission.
Generally, when the automobile engine is restarted after stalling, the power supply voltage of the system will drop to a lower value from a normal voltage within a short time, and then gradually rise to the normal voltage after a start condition is satisfied. This is shown in FIG. 1. As shown in FIG. 1, a normal power supply voltage of an automobile signal processor is usually 12V, for example, while during the start/stop operation of the automobile engine, the power supply voltage of the automobile signal processor will drop to a lowest voltage, e.g., 4.5V. In order to provide an automobile engine start/stop functionality, the automobile signal processor needs to work in a broad voltage range from the lowest voltage to the normal power supply voltage. Therefore, a DC voltage of a device will be biased to a lower value so as to support the broad operation range. However, a lower bias voltage will restrict swing of internal signals of the system, which means a signal to noise ratio will be lowered; in this way, signal quality during the normal operation will be degraded.
Therefore, there is a need in the art for an improved solution with respect to the automobile engine start/stop technology.